What intake manifold should I be using?
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Joined: Sep 2013
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From: Pennsylvania
What intake manifold should I be using?
Hey guys,
I recently purchased a blueprint 383 crate engine (http://www.jegs.com/i/Blueprint+Engi...34CT1/10002/-1) for my 81 vette and am starting to dress the engine. I plan on putting a 750 cfm carb on, and am looking at intake manifolds. Would the stock L-81 manifold be a good choice for this engine, or should I look into something else?
Current Specs:
-Otherwise stock driveshaft, TH350 auto transmission, possibility of improving rear gearing and trans in future
-OBX Headers/Sidepipes
-Street Application
Thanks,
Curtis
I recently purchased a blueprint 383 crate engine (http://www.jegs.com/i/Blueprint+Engi...34CT1/10002/-1) for my 81 vette and am starting to dress the engine. I plan on putting a 750 cfm carb on, and am looking at intake manifolds. Would the stock L-81 manifold be a good choice for this engine, or should I look into something else?
Current Specs:
-Otherwise stock driveshaft, TH350 auto transmission, possibility of improving rear gearing and trans in future
-OBX Headers/Sidepipes
-Street Application
Thanks,
Curtis
Thread Starter
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Joined: Sep 2013
Posts: 97
Likes: 1
From: Pennsylvania
Also, I already did a search, and found this: http://forums.corvetteforum.com/c3-t...-my-383-a.html
Wanted to know if there was more updated advice since 09.
Wanted to know if there was more updated advice since 09.
Melting Slicks
Joined: Jul 2010
Posts: 2,503
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From: McGrady NC
St. Jude Donor '15-'16
I would suggest a Performer RPM. You don't have a lot of hood clearance so your choices are somewhat limited. I'm in the same situation with my 80. The later stock L-82 is just an aluminum version of the cast iron intake. The earlier version with the square bore pattern may have fitment issues (height) on our cars, even with a drop base air cleaner.
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From: Pennsylvania
Searched on jegs, there's a lot of different models out there for the performer rpm. Whats the difference in the construction of the intake in terms of rpm range? Finish doesn't matter for me, i don't need polished or the endura-shine model. Also, it specifically says the intake won't fit under stock vette hoods. Thats a bit disconcerting.
Melting Slicks
Joined: Jul 2010
Posts: 2,503
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From: McGrady NC
St. Jude Donor '15-'16
The RPM will fit with a dropped base air cleaner. The base Performer, which isn't much better than a stock intake but looks better, will work with the stock air cleaner setup or aftermarket open types. The Performer RPM Air Gap is taller than the regular RPM version and room is very tight to non-existent. Some can run it and some can't, even with a dropped base air cleaner. You just have to get the type that is made for the carb you choose to use, as in spread bore for a QuadraJet or square bore for a Holley, Edelbrock, etc.
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From: Pennsylvania
Racer
Joined: Jul 2008
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From: Bowling Green Kentucky
I had a RPM Air Gap on my '81 with a drop base air filter with no clearance issues. I now have a Victor Jr. and it is nearly 1/2" shorter in height versus the RPM Air Gap. You will loose a bit of off idle performance with the Victor Jr. As it is a single plane manifold, but IMO it is negligible with proper tuning.
Safety Car
Joined: Oct 2004
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From: Youngstown Ohio
Yes. 230@ .050 is quite larger than stock. Your engine will idle better (without lurching) when in gear with the greater stall speed, and accelerate into its power band quicker.
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Safety Car
Joined: Oct 2004
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From: Youngstown Ohio
I've had great results with TCI's Breakaway converter on my previous 383, approx. 2400 stall. Best would be a custom converter if you wanted optimum results for the strip (Vigilante, Art Carr, etc.)
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From: Pennsylvania
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From: Pennsylvania
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Race Director
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I second the RPM Air Gap IMHO the best dual plane manifold out there. I did a side by side test the same day on the same chassis dyno with a Vic Jr.
Contrary to old wives tale the Vic Jr produced a little more torque but the manifolds were pretty much same until you reach 6000RPM where the Vic Jr takes over.
Contrary to old wives tale the Vic Jr produced a little more torque but the manifolds were pretty much same until you reach 6000RPM where the Vic Jr takes over.